TY -的T1 - F < em > < / em > <子> ENO子> < /生物量rker guide for inhaled corticosteroid step down in patients with mild-to-moderate well-controlled asthma JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.01319-2020 VL - 55 IS - 5 SP - 2001319 AU - Dinh-Xuan, Anh Tuan AU - Brusselle, Guy Y1 - 2020/05/01 UR - //www.qdcxjkg.com/content/55/5/2001319.abstract N2 - Nitric oxide (NO) is an endogenous gaseous molecule synthesised by practically all living cells [1]. It has an impressive wide range of physiological properties, justifying both its recognition as “molecule of the year” in 1992 [2], and in the 1998 Nobel Prize being awarded for nitric oxide discoveries 6 years later [3]. The first reports on the detection of NO in the exhaled air of healthy humans was published in 1991 [4], followed 2 years later by the very first description of increased exhaled NO in asthmatic patients [5]. In 1997, the European Respiratory Society issued the first technical recommendations regarding exhaled and nasal NO measurements [6]. Two years later the American Thoracic Society (ATS) introduced the fractional concentration of NO in the exhaled air (FENO) as a noninvasive, reproducible and reliable online measurement of NO stemming from the large airways [7]. During the past two decades, numerous national and international societies have issued recommendations related to its practical measurement or clinical use in asthma [7–12]. Yet, some uncertainties or, at the very least, questions still remain regarding the utility of this simple point-of-care testing tool in asthma.Reducing inhaled corticosteroid dose can be considered when FENO is less than 50 ppb in patients with well-controlled mild-to-moderate asthma. However, larger studies with longer follow-up are required in order to validate these preliminary data. https://bit.ly/2SckpnE ER -